The effectiveness of conventional mechanical hygiene alone and in combination with topical applications of sodium bicarbonate-sodium "paste" to control accumulations of oral bacteria will be compared in subjects with moderate peridontitis. Each subject will also undergo peridontal pocket reduction surgery in two of four posterior quadrants to allow assessment of this commonly used mode of peridontal disease therapy. Evaluation criteria will be (1) motile microscopic forms and white blood cells obtained from periodontal pockets will be viewed and numerically estimated by phase microscopy, (2) gingival sulci bleeding index and (3) measurements of gingival attachments relative to the cemento-enamel junction and gingival margin.